JP2007335598A - Inverter transformer - Google Patents

Inverter transformer Download PDF

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Publication number
JP2007335598A
JP2007335598A JP2006165123A JP2006165123A JP2007335598A JP 2007335598 A JP2007335598 A JP 2007335598A JP 2006165123 A JP2006165123 A JP 2006165123A JP 2006165123 A JP2006165123 A JP 2006165123A JP 2007335598 A JP2007335598 A JP 2007335598A
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Japan
Prior art keywords
core
portion
bobbin
inverter transformer
installed
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
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JP2006165123A
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Japanese (ja)
Inventor
Hiroki Miura
Masaki Saito
Shinpin Shin
シンピン シン
宏樹 三浦
正樹 斎藤
Original Assignee
Sumida Corporation
スミダコーポレーション株式会社
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Application filed by Sumida Corporation, スミダコーポレーション株式会社 filed Critical Sumida Corporation
Priority to JP2006165123A priority Critical patent/JP2007335598A/en
Publication of JP2007335598A publication Critical patent/JP2007335598A/en
Application status is Pending legal-status Critical

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a smaller inverter transformer by simplifying shape of a bobbin and a terminal stage while assuring insulation distance between a terminal and a core, by suppressing the effect of errors in manufacturing the core. <P>SOLUTION: The inverter transformer 1 comprises a rod-like first core disposed in a bobbin 4 of which a primary winding 2 and a secondary winding 3 are wound on a common shaft, and a frame-like second core 8 which is arranged to enclose the bobbin 4. The first core 7 is installed in such state as an end face 72a of a wide part 72 is abutted with one end in axial direction of the bobbin 4. The second core 8 is so installed that the wide part 72 of the first core 7 is used as a reference for alignment at installation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inverter transformer used in a DC / AC inverter circuit for discharging and lighting a cold cathode discharge lamp (CCFL) for backlights of various display panels used in, for example, notebook personal computers and liquid crystal televisions.

  In notebook personal computers and the like that are becoming thinner, it is common that an inverter circuit for driving a backlight is arranged in a frame portion of a display panel. For this reason, the circuit board itself has an elongated shape that fits in the frame portion, and accordingly, the inverter transformer mounted on the circuit board is also required to have a thin and elongated shape.

  Conventionally, what was described in the following patent document 1 is known as an inverter transformer suitable for such a thin and elongate shape. The inverter transformer includes a hollow bobbin around which a primary winding and a secondary winding are wound coaxially, a rod-shaped first core, and a frame-shaped second core, and the first core Is inserted and disposed in the bobbin with both end portions in the length direction exposed, and the second core is disposed so as to surround the bobbin.

JP-A-8-222440

  In recent years, with the demand for further thinning of notebook computers and the like, further reduction in size, in particular, reduction in height and width of the inverter transformer used has been demanded. In order to meet such a demand, it is necessary to solve several problems.

  The first is to simplify the shape of the bobbin and the terminal block. In general, the bobbin and the terminal block are integrally formed by injection molding. However, when the shape is complicated, the structure of the mold for injection molding becomes complicated, and the manufacturing cost increases accordingly. In particular, if the bobbin and the terminal block are downsized, the mold structure will become finer, so if the shape is complicated, the number of times that the mold can be used is greatly reduced, and the manufacturing cost may increase. .

  Secondly, securing the withstand voltage between the terminal and the core can be mentioned. In the inverter transformer for driving the backlight, the high voltage side of the secondary winding has a very high voltage, so that sufficient insulation is provided between the secondary side terminal connected to the core and the core, either spatially or creepagely. It is necessary to secure a distance. However, as the miniaturization is promoted, the allowable spatial or creepage distance between the secondary terminal and the core is limited, and it is inevitably necessary to provide an insulation distance with a margin in the design stage. It becomes difficult to set.

  At that time, a manufacturing error of the core becomes a big problem. In particular, the core formed in a rod shape has a large manufacturing error in the length direction. For example, when the core has a length of about 30 mm, the manufacturing error reaches about ± 0.4 mm at the maximum. When the spatial insulation distance changes by 0.1 mm, the dielectric strength voltage changes by about 100 V. Therefore, if there is a manufacturing error of 0.4 mm, the dielectric strength voltage changes by 400 V. For this reason, in an inverter transformer to be reduced in size, it becomes a big problem how to secure an insulation distance without being affected by a manufacturing error of the core and guarantee an insulation withstand voltage between the terminal and the core.

  However, in the inverter transformer described in Patent Document 1, the influence of such a manufacturing error related to ensuring a dielectric strength between the terminal and the core is not considered, and when further miniaturization is promoted, There is a possibility that the withstand voltage between the rod-shaped first core and the terminal varies between products.

  Further, in this inverter transformer, a connecting portion is provided between the terminal mounting portion and the winding portion so that the frame-shaped second core can be mounted at a predetermined position without interfering with the terminal mounting portion. The shape of the bobbin and the terminal block is very complicated. For this reason, it is difficult to achieve further downsizing in terms of the manufacturing cost described above.

  The present invention has been made in view of such circumstances, and the influence of the manufacturing error of the core is suppressed, the insulation distance between the terminal and the core is secured, and the shapes of the bobbin and the terminal block are simplified. It is an object of the present invention to provide an inverter transformer that can achieve downsizing.

An inverter transformer according to the present invention includes a hollow bobbin in which a primary winding and a secondary winding are wound coaxially, a terminal block disposed on both sides in the axial direction of the bobbin, and both end portions in the length direction An inverter transformer comprising: a rod-shaped first core disposed in a hollow portion of the bobbin in a state where is exposed; and a frame-shaped second core disposed so as to surround the bobbin;
The first core includes a narrow width portion having a width that can be inserted into the hollow portion, and a wide width portion formed wider than the narrow width portion at one end portion in the length direction. It is installed in a state where the end surface on the narrow portion side is in contact with one end portion in the axial direction of the bobbin,
The second core is configured to be installed using the wide portion of the installed first core as a reference for alignment at the time of installation.

  In the inverter transformer of the present invention, the second core has a first short side portion straddling the wide portion in the width direction, and an inner side surface of the first short side portion is one end portion in the axial direction of the bobbin. It can be configured so as to be installed in a state of being in contact with.

  Also, in the inverter transformer of the present invention, the first core has one end portion in the length direction on a side where a terminal connected to the high voltage end of the secondary winding is disposed on both sides in the axial direction of the bobbin. It is preferable that it is installed so as to be located.

  According to the inverter transformer of the present invention, the rod-shaped first core is composed of the narrow portion and the wide portion, and the end surface on the narrow portion side of the wide portion is in contact with one end portion in the axial direction of the bobbin. Since the first core is installed on the bobbin, the following effects can be obtained.

  That is, since the wide portion formed at one end portion in the length direction of the first core can be set shorter than the entire length of the first core, the wide portion even when the total length of the first core varies due to manufacturing errors. The fluctuation of the length can be kept small. Since the first core is installed in a state in which the end surface of the wide portion on the narrow portion side is in contact with one end portion in the axial direction of the bobbin, a predetermined space is previously provided between the one end portion in the axial direction of the bobbin and the terminal. If the target distance is set, even if a manufacturing error of the first core occurs, it is possible to suppress a variation in the spatial distance between the wide portion and the terminal.

  Therefore, it is possible to accurately secure a predetermined insulation distance required between the first core and the terminal while suppressing the influence of the manufacturing error of the first core.

  In addition, since the frame-shaped second core is installed using the wide portion of the installed first core as a reference for alignment at the time of installation, the insulation distance between the second core and the terminal is also the first core. The manufacturing error can be suppressed with high accuracy and there is no need to provide a structure for alignment when installing the second core on the bobbin and terminal block. It becomes possible to simplify.

  This eliminates the concern of downsizing the bobbin and terminal block molding molds, which greatly reduces the number of times the molds can be used, resulting in high manufacturing costs. Therefore, further miniaturization can be achieved while suppressing the manufacturing cost.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an inverter transformer according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view of an inverter transformer according to an embodiment of the present invention, and FIG. 2 is a perspective view of the bobbin and terminal block shown in FIG. 1 (when windings and terminals are not mounted). 3 is a perspective view of the first core shown in FIG. 1, and FIG. 4 is a perspective view of the second core shown in FIG. Note that the three-dimensional orthogonal coordinate system shown in each figure indicates the correspondence between the orientations of the drawings, and in the following description, the direction of the X axis of the three-dimensional orthogonal coordinate system is the front and back (the direction of the arrow line is ), The direction of the Y axis may be referred to as left and right (the direction of the arrow is right), and the direction of the Z axis may be referred to as up and down (the direction of the arrow is upward).

  The inverter transformer 1 of the present embodiment is used in a DC / AC inverter circuit that discharges and lights a cold cathode discharge lamp (CCFL) for backlights of various display panels used in, for example, notebook computers and liquid crystal televisions. As shown in FIG. 1, a hollow bobbin 4 in which a primary winding 2 and a secondary winding 3 (partially omitted) are wound coaxially, and the axial direction (Y (Axial direction) first terminal block 5 and second terminal block 6 (hereinafter sometimes simply referred to as “terminal blocks 5 and 6”) and rod-shaped first core 7 (partially disposed) on both sides And a frame-shaped second core 8.

  As shown in FIG. 2, the bobbin 4 has a first winding by means of end rods 41A and 41B arranged at both left and right ends, and an intermediate rod 42 arranged between the pair of end rods 41A and 41B. It is divided into a shaft portion 43 and a second winding shaft portion 44, and the primary winding 2 (see FIG. 1) is wound around the first winding shaft portion 43. The second winding shaft portion 44 is divided into a plurality of (seven in this embodiment) winding sections by a plurality (six in this embodiment) of partitioning rods 45, and each secondary winding section is divided into the secondary windings. The winding 3 (see FIG. 1) is wound. Each partition rod 45 is formed with a notch 46 for passing the secondary winding 3 to an adjacent winding section.

  The bobbin 4 has a hollow portion 47 that penetrates the bobbin 4 in the axial direction of the bobbin 4, and the first core 7 is disposed in the hollow portion 47 at both ends in the length direction. It is arranged to be inserted and exposed from the bobbin 4 (see FIG. 1).

  On the other hand, as shown in FIG. 2, the first terminal block 5 and the second terminal block 6 each have a plate shape and are formed integrally with the bobbin 4. The first terminal block 5 is provided on the side where the first winding shaft portion 43 is formed on both sides in the axial direction of the bobbin 4, and the second terminal block 6 is connected to the bobbin 4. It is provided in the side in which the said 2nd winding shaft part 44 was formed among axial direction both sides.

  In the present embodiment, as shown in FIG. 1, the first terminal block 5 holds four terminals 9 </ b> A to 9 </ b> D, and the second terminal block 6 has two terminals. 9E and 9F are held. Among these terminals 9A to 9F, the terminal 9D is electrically connected to the low-voltage end side of the CCFL (not shown), and the low-voltage end of the secondary winding 3 is entangled with the binding portion 91. It is like that. Further, the terminal 9E is electrically connected to the high voltage end side of the CCFL (not shown), and the high voltage end of the secondary winding 3 is entangled with the entangled portion 92 thereof.

  As shown in FIG. 3, the first core 7 has a narrow width portion 71 having a width (length in the X-axis direction) that can be inserted into the hollow portion 47 (see FIG. 2) of the bobbin 4, and a length. The end surface 72a of the wide width portion 72 on the narrow width portion 71 side is connected to one end in the axial direction of the bobbin 4 at one end portion in the direction (Y-axis direction). It is configured to be installed in a state where it is in contact with the portion (specifically, the end face 41a of the end rod 41B on the second terminal block 6 side shown in FIG. 2) (see FIG. 1).

  As shown in FIG. 4, the second core 8 includes a first long side portion 81 and a second long side portion 82 that extend parallel to each other in the length direction (Y-axis direction), and the first long side portion 81. And a first short side portion 83 and a second short side portion 84 that connect the end portions of the second long side portion 82 and are arranged so as to surround the bobbin 4 (see FIG. 1).

  Specifically, the second core 8 is configured to be installed using the wide portion 72 of the first core 7 (see FIG. 1) installed as described above as a reference for alignment during installation. That is, the second core 8 has an inner side surface 83a of the first short side portion 83 (see FIG. 4) on the end surface 41a of the end collar 41B with which the end surface 72a of the wide width portion 72 of the first core 7 is in contact. It is comprised so that it may install in the state which contact | abutted (refer FIG. 1).

  In addition, the first short side portion 83 is formed thinner in the thickness direction (Z-axis direction) than the first long side portion 81 and the second long side portion 82, and the wide width in the installation state described above. The part 72 is configured to straddle the width direction (X-axis direction). At this time, the lower surface 83b (see FIG. 4) of the first short side portion 83 abuts on the upper surface 72b (see FIG. 3) of the wide portion 72 (an air gap for adjusting leakage inductance may be provided). Good). Similarly, the second short side portion 84 is also formed thin in the thickness direction, and the end portion 71a (see FIG. 3) on the side exposed from the bobbin 4 of the narrow width portion 71 in the above-described installation state is provided. It is comprised so that it may straddle the width direction (X-axis direction). At that time, the lower surface 84b (see FIG. 4) of the second short side portion 84 comes into contact with the upper surface of the end portion 71a of the narrow width portion 71 (an air gap for adjusting leakage inductance may be provided). Good).

  Hereinafter, the effect of the inverter transformer 1 according to the present embodiment will be described. For the first core 7 and the second core 8 described above, for example, a dust core obtained by compression molding a fine powder such as ferrite, permalloy, or sendust can be used. Such a molded core has a large manufacturing error. For example, when the design dimension of the entire length of the first core 7 is 30 mm, the manufacturing error reaches about ± 0.4 mm.

  On the other hand, the wide portion 72 of the first core 7 is formed by a portion exposed from the bobbin 4, and the length thereof can be set to be considerably shorter than the entire length of the first core 7. For example, if the length (dimension in the Y hour direction) of the wide portion 72 in FIG. 3 is 3 mm, the manufacturing error can be suppressed to ± 0.1 mm or less.

  As shown in FIG. 1, in the first core 7, the wide portion 72 is located on the side where the terminal 9 </ b> E connected to the high-voltage end of the secondary winding is disposed on both axial sides of the bobbin 4. It is installed as follows. For this reason, it is necessary to set a predetermined insulation distance spatially or creepingly between the wide portion 72 and the terminal 9E in order to ensure a predetermined withstand voltage. If the set insulation distance largely fluctuates due to the manufacturing error of the first core 7, the necessary withstand voltage cannot be ensured. On the other hand, it is conceivable to set the size of the bobbin 4 or the second terminal block 6 in advance so as to allow for the variation of the entire length of the first core 7 due to manufacturing errors. In that case, miniaturization becomes difficult.

  On the other hand, in the present embodiment, as shown in FIG. 1, the first core 7 is installed in a state where the end surface 72a of the wide width portion 72 is in contact with the end surface 41a of the end rod 41B. Variation in the distance between the wide portion 72 and the terminal 9 </ b> E due to the manufacturing error can be suppressed to the range of variation in the length of the wide portion 72. Accordingly, if the distance from the end flange 41B to the terminal 9E is set in advance so that only the variation in the length of the wide width portion 72 can be allowed, the necessary withstand voltage is ensured even if a manufacturing error occurs. be able to. Further, since it is not necessary to set the size of the bobbin 4 or the second terminal block 6 so as to allow an error variation of the entire length of the first core 7, it is possible to reduce the size.

  The second core 8 is configured in advance so as to be installed at a position farther from the terminal 9E than the first core 7 is. As described above, the second core 8 is configured to be installed using the wide portion 72 of the first core 7 as a reference for alignment at the time of installation, and therefore, between the first core 7 and the terminal 9E. If the insulation distance is secured, the insulation distance between the second core 8 and the terminal 9E can also be secured. Further, since the reference for alignment of the second core 8 is the first core 7, it is necessary to provide an engaging portion for alignment between the second core 8 and the bobbin 4 and the terminal blocks 5 and 6. Therefore, the structure of the bobbin 4 and the terminal blocks 5 and 6 are simplified because they are not provided.

  Therefore, the structure of the molding die for the bobbin 4 and the terminal blocks 5 and 6, which is a concern when miniaturization is attempted, becomes finer, and the number of times that the die can be used is greatly reduced. This increases the manufacturing cost. Thus, further miniaturization can be achieved while suppressing the manufacturing cost.

The top view of the inverter transformer concerning one embodiment 1 is a perspective view of the bobbin and terminal block shown in FIG. 1 is a perspective view of the first core shown in FIG. The perspective view of the 2nd core shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter transformer 2 Primary winding 3 Secondary winding 4 Bobbin 5 1st terminal block 6 2nd terminal block 7 1st core 8 2nd core 9A-9F terminal 41 Winding shaft part 41A, 41B End rod 41a End surface 42 Intermediate rod 43 First winding shaft portion 44 Second winding shaft portion 45 Partition rod 46 Notch portion 47 Hollow portion 71 Narrow portion 71a End portion 72 Wide portion 72a End surface 72b Upper surface 81 First long side portion 82 Second length Side portion 83 First short side portion 83a Inner side surface 83b Lower surface 84 Second short side portion 91, 92 Binding portion

Claims (3)

  1. A hollow bobbin in which the primary winding and the secondary winding are coaxially wound, a terminal block disposed on both sides in the axial direction of the bobbin, and both ends of the bobbin in a state where both end portions in the length direction are exposed An inverter transformer comprising a rod-shaped first core disposed in a hollow portion and a frame-shaped second core disposed so as to surround the bobbin,
    The first core includes a narrow width portion having a width that can be inserted into the hollow portion, and a wide width portion formed wider than the narrow width portion at one end portion in the length direction. It is installed in a state where the end surface on the narrow portion side is in contact with one end portion in the axial direction of the bobbin,
    The inverter transformer, wherein the second core is configured to be installed using the wide portion of the installed first core as a reference for alignment at the time of installation.
  2.   The second core has a first short side portion straddling the wide portion in the width direction, and the inner side surface of the first short side portion is in contact with the one axial end portion of the bobbin. The inverter transformer according to claim 1, wherein the inverter transformer is configured to be installed.
  3. The first core is installed such that one end portion in the length direction is positioned on a side where a terminal connected to the high voltage end of the secondary winding is disposed on both axial sides of the bobbin. The inverter transformer according to claim 1 or 2, wherein
JP2006165123A 2006-06-14 2006-06-14 Inverter transformer Pending JP2007335598A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2006165123A JP2007335598A (en) 2006-06-14 2006-06-14 Inverter transformer

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Application Number Priority Date Filing Date Title
JP2006165123A JP2007335598A (en) 2006-06-14 2006-06-14 Inverter transformer

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JP2007335598A true JP2007335598A (en) 2007-12-27

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04245607A (en) * 1991-01-31 1992-09-02 Taiyo Yuden Co Ltd Transformer
JP2002353044A (en) * 2001-05-25 2002-12-06 Minebea Co Ltd Inverter transformer
JP2004214488A (en) * 2003-01-07 2004-07-29 Minebea Co Ltd Inverter transformer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04245607A (en) * 1991-01-31 1992-09-02 Taiyo Yuden Co Ltd Transformer
JP2002353044A (en) * 2001-05-25 2002-12-06 Minebea Co Ltd Inverter transformer
JP2004214488A (en) * 2003-01-07 2004-07-29 Minebea Co Ltd Inverter transformer

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